Drawbridge



2 Sheets-Sheet l.

E. B. JENNINGS... DRAWBRIDGB.

Patented Feb. 11, 189-6.-

(No Mod l I 2 Sheets-8heet 2.

E. B. JENNINGS. I

DRAWBRIDGE.

No. 554,390. Patented Feb. 11, 1896.

UNITED STATES ATENT FFICE.

EDIVIN B. JENNINGS, OF SPRINGFIELD, MASSACHUSETTS.

DRAWBRIDG E.

SPECIFICATION forming part of Letters Patent No. 554,390, dated February11, 1896. Application filed October 15, 1895. Serial No. 565,702. (Nomodel.)

To all whom it may concern.-

Be it known that I, EDWIN B. JENNINGS, a citizen of the United States,residing at Springfield, county of I-Iarnpden, and State ofMassachusetts, have invented a new and useful Improvement inDrawbridges, of which the following is a specification.

My improvements relate to the class of drawbridges in which two sectionsrotate vertically from a closed position forming a bridge to an openposition leaving a passage-way, and in which the two sections rotate inopposite directions upon pivots, and have for their object the provisionof a secure fastening or joint for the free ends of the sections whenprolonged; and the invention consists in the combination andconstruction as hereinafter described, and more particularly pointed outin the claims.

My invention is fully illustrated in the accompanying drawings, in whichFigure I is a side elevation of a drawbridge having my improvements.Fig. II is a plan view of one section with the top chord removed. Fig.III is an end elevation of one section viewed from its free end. Fig. IVis an enlarged end view of one section. Fig. V is the same, showing amodification. Fig. VI is a top plan view of the mechanism shown in Fig.V, and Fig. VII is an enlarged detail.

I11 the drawings, 13 O are the two sections, pivoted respectively at Z)c to piers or to the walls upon-opposite sides of a waterway to rotatevertically in opposite directions upon said pivots. As shown, saidpivots are removed from the outer ends of the sections, andcounterweights (Z d are interposed between the pivots and outer ends ofthe sections to render the rotation of the sections easier, whichrotation is effected by gears D D concentric to the pivots and securedthereto, engaged by gears e e driven by a belt and pulley. A well IV ateach end permits the depression of the section ends. These gen eralfeatures of a drawbridge are old and are only shown and mentioned inillustration of my invention, in which light upper chords, h h, andlower chords, g g, are prolonged to form a complete truss without anyvertical extension of the joint-surfaces to secure a larger bearing andwithout any extraneous support above or below the chords, and by meansof which the bridge can be made of the structure, and this I do byproviding.

corresponding eyes 11 H upon the ends of the lower chords, g g, andarranging transverse bolts I I in bearings in one section, to beoperated from the pivot end of said section, to be shot into the eyeswhen they come opposite, to secure the sections, or retracted from saideyes when it is desired to free them for rotation.

As a means for operating the bolts I I, a rod G is shown arrangedmedially between the chords g of section 0 to extend from opposite thefree end of said section to a point a little past the pivot 0, beingjournaled at its two ends and at as many intermediate points as isrequired to maintain it straight in the floor-beams. Upon the end nearthe pivot c is a gear 0, engaging with a gear 8 on a counter-shaft t,journaled transversely in the lower chords, g, and one end of thecounter-shaft is prolonged outside of chord g and is provided upon saidend with a gear a. The gear it engages with a gear 4) upon a shaft w infixed bearings and provided with a driving-pulley y operated by a belt.

It will be seen that upon the rotation of section O-the gear to is swungaway from gear '11 to re-engage with it when section 0 resumes ahorizontal position. This is more particularly shown in Figs. II andIII.

The pulley Y rotates rod G to slide the bolts I I.

In Figs. II, III and IV a pinion J, engaging with racks r 1" upon theshanks of bolts I I, is shown, the racks being upon opposite sides ofthe pinion, so as to move the bolts simultaneously in oppositedirections, and are guided by sleeves a a.

In Figs. V and VII in place of the pinion J upon the end of rod G acrank-wheel K is shown connected by toggles to the bolts I I,

so that a partial rotation of the crank-wheel will slide the bolts intheir sleeves n n.

In Fig. VII the eyes forming the terminal ends of chords g g are shownin side view, the eye 11 being preferably bifurcated or with two leaves,so as to give a better bearing to the bolts,

The bolts I I are preferably pointed, as shown, so that said points willact as followers to cause the eyes of the two sections to coincide. Asthe points of the bolts can rest in one leaf of eye H, the distancerequired to be slid by the bolts in securing or releasing thebridge-sections is very short, and a powerful cam may be employed toshoot them, although excessive force is not required, as no weight is onthe bridge when the bolts are required to be operated.

In the drawings, Fig. I, stops L L are shown against which the innerends of the sections come to bring their free ends in prolongation, sothat with the eyes of the lower chords of the configuration shown it isimmaterial whether the sections are lowered simultaneously or at random.7

Now, having described my invention, what I claim is- 1. A truss-bridgebisected at or near its middle part, the sections of the compressionmember being adapted to abut and bear against each other in the closedposition, and the meeting ends of the tension member being provided witheyes registering when in the closed position, said sections beingpivotally mounted upon the abutments and provided with readily removablepins to engage with and be disengaged from the eyes of the tensionmember as set forth.

2. The combination with a centrallybisected truss forming as shown anddescribed, the two vertically-rotating sections of a drawbridge, offaced ends upon the upper chords, and eyes upon the lower chordsarranged to have said faced ends bear and the eyes eor- EDXVIN B.JENNINGS.

Witnesses:

R. F. HYDE, PENN TYLER.

